Alert archive / Pennsylvania / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 300

May 26, 20124 states

The Storm Prediction Center issued this severe thunderstorm watch at May 26, 2012, 2:29 PM EDT for 4 states. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
May 26, 2012, 2:29 PM EDT (18:29 UTC)
Expired
May 26, 2012, 8:00 PM EDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
65 kt
All 48 counties

Greater Bridgeport Planning Region, CT, Naugatuck Valley Planning Region, CT, Bergen County, NJ, Essex County, NJ, Hudson County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Morris County, NJ, Passaic County, NJ, Somerset County, NJ, Sussex County, NJ, Union County, NJ, Warren County, NJ, Bronx County, NY, Kings County, NY, Nassau County, NY, New York County, NY, Orange County, NY, Putnam County, NY, Queens County, NY, Richmond County, NY, Rockland County, NY, Westchester County, NY, Adams County, PA, Berks County, PA, Bucks County, PA, Carbon County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Juniata County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Luzerne County, PA, Mifflin County, PA, Monroe County, PA, Montgomery County, PA, Montour County, PA, Northampton County, PA, Northumberland County, PA, Perry County, PA, Pike County, PA, Schuylkill County, PA, Snyder County, PA, Union County, PA, York County, PA

The radar

The Philadelphia radar (KDIX), 124 km from the middle of the area, began a volume at 18:30 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
10%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

12 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
May 26, 2:35 PM EDTSevere Thunderstorm WarningCTPJuniata, Snyder, Union55 min
May 26, 2:36 PM EDTFlash Flood WarningPHIWarren5 hr
May 26, 2:42 PM EDTSevere Thunderstorm WarningPHIWarren48 min
May 26, 2:49 PM EDTSevere Thunderstorm WarningOKXBergen41 min
May 26, 3:32 PM EDTFlash Flood WarningPHIMonroe, Northampton4 hr
May 26, 3:45 PM EDTSevere Thunderstorm WarningCTPSchuylkill60 min
May 26, 3:54 PM EDTFlash Flood WarningPHICarbon4 hr
May 26, 3:57 PM EDTFlash Flood WarningCTPSchuylkill3 hr
May 26, 4:00 PM EDTSevere Thunderstorm WarningOKXRockland, Westchester47 min
May 26, 5:33 PM EDTFlash Flood WarningPHIMonroe114 min
May 26, 5:35 PM EDTFlash Flood WarningCTPColumbia, Schuylkill85 min
May 26, 7:33 PM EDTSevere Thunderstorm WarningCTPLancaster57 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 6.5 hours before the alert went out and 221 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Brookhaven, NY at 12:00Z on 2012-05-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 144 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 12:00Z on 2012-05-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 42 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
144 J/kg
Mixed-layer CIN
-138 J/kg
Mixed-layer LCL
659 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
42 m²/s²
0-3 km storm-relative helicity
105 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 26, 1:17 PM EDTMesoscale DiscussionSPC88 min
May 26, 2:08 PM EDTMesoscale DiscussionSPC37 min
May 26, 6:04 PM EDTMesoscale DiscussionSPC56 min
May 25, 9:18 PM EDTMesoscale DiscussionSPCCayuga, Franklin, Hamilton, Herkimer, Jefferson, Lewis and 5 more117 min

Nearby

Severe Thunderstorm Watches in Pennsylvania, 2012Severe Thunderstorm Watches in New Jersey, 2012Severe Thunderstorm Watches in New York, 2012Every severe thunderstorm watch in 2012

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.